Mike Posner Performs At Father's Funeral After 'Conan' Cancer Reveal

Mike Posner's father passed away last week, and his son honored him by performing at his funeral ... after revealing the man had cancer last year on TV.

Mike's dad, Jon, died last Wednesday from his months-long battle with cancer at the age of 73 -- and Mike chose to remember him in song by covering a classic.

The singer performed Bright Eyes' "First Day Of My Life" in front of an audience Friday at the Ira Kaufman Chapel in Southfield, Michigan, where Jon was an attorney.

Back in May, Mike had alluded to his father's illness while performing on "Conan," where he changed the lyrics to his hit song "I Took a Pill in Ibiza" to ...

And my dad has cancer
I'm still wrapping my head 'round that
Sat by the hospital bed, nurses poked in their heads
And asked me to sign autographs
And my dad has cancer!
I shouldn't be here, I should be home
But in case you couldn't tell, I'm busy playing myself
In this little Mike Posner show

Nothing's cooler than that.